Try wrapping a curve instead of projecting it
I created this using the wrap feature since projecting a curve (as well as some other things that reference the outer surface) can be problematic as the pattern moves to the other half of the round surface. This may not be the most efficient or simple way but it gets the job done.
0. Create a tube.
1. Create a wrap using datums that are offset at an angle (later pick this offset angle for the pattern around the tube).
2. Create a datum offset from the end of the tube (later pick this dimension for the pattern along the length).
3. Create a datum set with two points. First point is the datum from step 2 and the wrapped curve. The other point is the tube axis and the datum from step 2.
4. Create a datum axis that goes through the two points in step 3.
5. Create a final datum that is normal to the axis in step 4 and through the first point in step 3.
6. Group the features except for the tube.
7. Pattern the group using the offset angle from step1, and the second direction using the offset from step 2.
8. Create a hole referencing the first axis of the pattern from step4 as well as the surface from step 5.
9. Pattern the hole as a reference.
https://docs.google.com/file/d/0B174v5E0EvkBbFEtNlF0LUpOT0k/edit?usp=sharing
Done...used Creo 2.0. You could just use one pattern along with the hole but I think it sometimes makes it easier to find the hole later if you choose modify it. Good luck!